1. Field of Invention
The present invention relates to beach umbrellas and more particularly to such a beach umbrella having advantages of having a minimum space after folding and being capable of carry out a segment-less length adjustment of shank.
2. Description of Related Art
Conventionally, a beach umbrella is simply an enlargement of an umbrella available in the market. The beach umbrella comprises a folding radial frame, a canopy stretched over the frame, and a threadedly connected shank having a pointed end adapted to insert into sand for fastening.
However, the prior beach umbrella suffered from several disadvantages. For example, segments of the shank are detachable. Thus, persons tend to forget to bring one or more shank segments after folding same and leaving beach. Further, segment-less adjustment of length of the shank is not provided. Thus, some people may not satisfy with the length adjustment feature. Furthermore the shank has a large diameter and a thick wall. Thus, a retraction mechanism as implemented in prior umbrella shank with a small diameter and a thin wall is not applicable for the beach umbrella. In addition, no hinge is provided in the rib. Thus, storage reduction of the beach umbrella is limited after folding.
Taiwanese Utility Model Patent No. 110,544 (publication No. 270295) discloses a beach umbrella frame comprising a cylindrical shank having a bottom extension, a plurality of ribs each including three segments, a plurality of spreaders each including two segments, a first hinge pivotably interconnecting first and second rib segments, and a second hinge pivotably interconnecting second and third segments. The storage reduction of the folded beach umbrella is somewhat improved and it is easy to carry after folding.
Taiwanese Utility Model Patent No. 98,904 (publication No. 241469) discloses a fastening mechanism for beach umbrella. It is characterized in that the shank segments are threadedly secured together, and each rib including a first segment, a second segment, and a hinge pivotably interconnecting first and second segments. In a fully stretched position of the umbrella, the ribs are fastened by the hinges.
However, both patents still have the problems of people tending to forget to bring one or more shank segments after folding same and leaving beach, the length adjustment feature of the shank being unsatisfactory, and limited storage reduction after folding. As mentioned above, both of their rib and hinge between each two interconnecting segments are made of metal. The hinge between two segments of rib is secured by rivet. The rivet fastening is a time consuming and a low yield process, the quality of the joint is not reliable, for example caused by rust, will cause jam of an umbrella. Thus, the need for improvement still exists.